This invention relates to the conversion of chemical energy to electrical energy, and more particularly to a new and improved anode construction for lithium-halogen cells and a method of making the same.
One area of use of the present invention is in providing electrical power to inaccessible devices in the human environment, for example to an implanted cardiac pacemaker, although the principles of the present invention can be variously applied. Lithium-iodine batteries are available for such use which advantageously have an open circuit voltage about twice that of the mercury cell, do not generate gas during operation, and have a non-corrosive electrolyte.
It is desirable to provide a lithium-halogen cell and anode construction having a relatively low cell impedance and having a relatively constant long-term cell impedance. The foregoing has been accomplished by applying to the lithium anode a coating of an organic electron donor material. It would be highly desirable to provide such a method which can be performed relatively quickly, which results in an anode coating of substantially uniform solidity and thickness, where thickness can be varied as required. It also would be highly desirable to provide such a method which results in an anode coating which reduces or substantially eliminates the possibility of nitride formation on the surface of the lithium element which is coated and provides a coated anode resulting in reduced cell electrical impedance when used in a lithium-halogen cell.